diff --git a/arrow-row/src/fixed.rs b/arrow-row/src/fixed.rs
index 461d9cd9c1c0..3d9920708f9b 100644
--- a/arrow-row/src/fixed.rs
+++ b/arrow-row/src/fixed.rs
@@ -18,9 +18,10 @@
 use crate::array::PrimitiveArray;
 use crate::null_sentinel;
 use arrow_array::builder::BufferBuilder;
-use arrow_array::{Array, ArrowPrimitiveType, BooleanArray, FixedSizeBinaryArray};
+use arrow_array::{ArrowPrimitiveType, BooleanArray, FixedSizeBinaryArray};
 use arrow_buffer::{
-    bit_util, i256, ArrowNativeType, Buffer, IntervalDayTime, IntervalMonthDayNano, MutableBuffer,
+    bit_util, i256, ArrowNativeType, BooleanBuffer, Buffer, IntervalDayTime, IntervalMonthDayNano,
+    MutableBuffer, NullBuffer,
 };
 use arrow_data::{ArrayData, ArrayDataBuilder};
 use arrow_schema::{DataType, SortOptions};
@@ -216,22 +217,20 @@ where
 ///
 /// - 1 byte `0` if null or `1` if valid
 /// - bytes of [`FixedLengthEncoding`]
-pub fn encode<T: ArrowPrimitiveType>(
+pub fn encode<T: FixedLengthEncoding>(
     data: &mut [u8],
     offsets: &mut [usize],
-    array: &PrimitiveArray<T>,
+    values: &[T],
+    nulls: &NullBuffer,
     opts: SortOptions,
-) where
-    T::Native: FixedLengthEncoding,
-{
-    let mut offset_idx = 1;
-    for maybe_val in array {
-        let offset = &mut offsets[offset_idx];
-        let end_offset = *offset + T::Native::ENCODED_LEN;
-        if let Some(val) = maybe_val {
+) {
+    for (value_idx, is_valid) in nulls.iter().enumerate() {
+        let offset = &mut offsets[value_idx + 1];
+        let end_offset = *offset + T::ENCODED_LEN;
+        if is_valid {
             let to_write = &mut data[*offset..end_offset];
             to_write[0] = 1;
-            let mut encoded = val.encode();
+            let mut encoded = values[value_idx].encode();
             if opts.descending {
                 // Flip bits to reverse order
                 encoded.as_mut().iter_mut().for_each(|v| *v = !*v)
@@ -241,26 +240,20 @@ pub fn encode<T: ArrowPrimitiveType>(
             data[*offset] = null_sentinel(opts);
         }
         *offset = end_offset;
-        offset_idx += 1;
     }
 }
 
 /// Encoding for non-nullable primitive arrays.
 /// Iterates directly over the `values`, and skips NULLs-checking.
-pub fn encode_not_null<T: ArrowPrimitiveType>(
+pub fn encode_not_null<T: FixedLengthEncoding>(
     data: &mut [u8],
     offsets: &mut [usize],
-    array: &PrimitiveArray<T>,
+    values: &[T],
     opts: SortOptions,
-) where
-    T::Native: FixedLengthEncoding,
-{
-    assert!(!array.is_nullable());
-
-    let mut offset_idx = 1;
-    for val in array.values() {
-        let offset = &mut offsets[offset_idx];
-        let end_offset = *offset + T::Native::ENCODED_LEN;
+) {
+    for (value_idx, val) in values.iter().enumerate() {
+        let offset = &mut offsets[value_idx + 1];
+        let end_offset = *offset + T::ENCODED_LEN;
 
         let to_write = &mut data[*offset..end_offset];
         to_write[0] = 1;
@@ -272,7 +265,6 @@ pub fn encode_not_null<T: ArrowPrimitiveType>(
         to_write[1..].copy_from_slice(encoded.as_ref());
 
         *offset = end_offset;
-        offset_idx += 1;
     }
 }
 
@@ -280,20 +272,20 @@ pub fn encode_not_null<T: ArrowPrimitiveType>(
 ///
 /// - 1 byte `0` if null or `1` if valid
 /// - bytes of [`FixedLengthEncoding`]
-pub fn encode_bool(
+pub fn encode_boolean(
     data: &mut [u8],
     offsets: &mut [usize],
-    array: &BooleanArray,
+    values: &BooleanBuffer,
+    nulls: &NullBuffer,
     opts: SortOptions,
 ) {
-    let mut offset_idx = 1;
-    for maybe_val in array {
-        let offset = &mut offsets[offset_idx];
+    for (idx, is_valid) in nulls.iter().enumerate() {
+        let offset = &mut offsets[idx + 1];
         let end_offset = *offset + bool::ENCODED_LEN;
-        if let Some(val) = maybe_val {
+        if is_valid {
             let to_write = &mut data[*offset..end_offset];
             to_write[0] = 1;
-            let mut encoded = val.encode();
+            let mut encoded = values.value(idx).encode();
             if opts.descending {
                 // Flip bits to reverse order
                 encoded.as_mut().iter_mut().for_each(|v| *v = !*v)
@@ -303,23 +295,19 @@ pub fn encode_bool(
             data[*offset] = null_sentinel(opts);
         }
         *offset = end_offset;
-        offset_idx += 1;
     }
 }
 
 /// Encoding for non-nullable boolean arrays.
 /// Iterates directly over `values`, and skips NULLs-checking.
-pub fn encode_bool_not_null(
+pub fn encode_boolean_not_null(
     data: &mut [u8],
     offsets: &mut [usize],
-    array: &BooleanArray,
+    values: &BooleanBuffer,
     opts: SortOptions,
 ) {
-    assert!(!array.is_nullable());
-
-    let mut offset_idx = 1;
-    for val in array.values() {
-        let offset = &mut offsets[offset_idx];
+    for (value_idx, val) in values.iter().enumerate() {
+        let offset = &mut offsets[value_idx + 1];
         let end_offset = *offset + bool::ENCODED_LEN;
 
         let to_write = &mut data[*offset..end_offset];
@@ -332,7 +320,6 @@ pub fn encode_bool_not_null(
         to_write[1..].copy_from_slice(encoded.as_ref());
 
         *offset = end_offset;
-        offset_idx += 1;
     }
 }
 
@@ -343,9 +330,7 @@ pub fn encode_fixed_size_binary(
     opts: SortOptions,
 ) {
     let len = array.value_length() as usize;
-    let mut offset_idx = 1;
-    for maybe_val in array {
-        let offset = &mut offsets[offset_idx];
+    for (offset, maybe_val) in offsets.iter_mut().skip(1).zip(array.iter()) {
         let end_offset = *offset + len + 1;
         if let Some(val) = maybe_val {
             let to_write = &mut data[*offset..end_offset];
@@ -359,7 +344,6 @@ pub fn encode_fixed_size_binary(
             data[*offset] = null_sentinel(opts);
         }
         *offset = end_offset;
-        offset_idx += 1;
     }
 }
 
diff --git a/arrow-row/src/lib.rs b/arrow-row/src/lib.rs
index 8e67858fa5af..935db80385bb 100644
--- a/arrow-row/src/lib.rs
+++ b/arrow-row/src/lib.rs
@@ -1147,18 +1147,18 @@ fn encode_column(
         Encoder::Stateless => {
             downcast_primitive_array! {
                 column => {
-                    if column.is_nullable(){
-                        fixed::encode(data, offsets, column, opts)
+                    if let Some(nulls) = column.nulls().filter(|n| n.null_count() > 0){
+                        fixed::encode(data, offsets, column.values(), nulls, opts)
                     } else {
-                        fixed::encode_not_null(data, offsets, column, opts)
+                        fixed::encode_not_null(data, offsets, column.values(), opts)
                     }
                 }
                 DataType::Null => {}
                 DataType::Boolean => {
-                    if column.is_nullable(){
-                        fixed::encode_bool(data, offsets, column.as_boolean(), opts)
+                    if let Some(nulls) = column.nulls().filter(|n| n.null_count() > 0){
+                        fixed::encode_boolean(data, offsets, column.as_boolean().values(), nulls, opts)
                     } else {
-                        fixed::encode_bool_not_null(data, offsets, column.as_boolean(), opts)
+                        fixed::encode_boolean_not_null(data, offsets, column.as_boolean().values(), opts)
                     }
                 }
                 DataType::Binary => {